You are a Monster (thing)

One of the great Choose Your Own Adventure books. In this one a mad scientist captures you and turns you in a hairy, fanged, scary monster. Then you're set loose. What you do next is up to you. Do you terrorize people? Get sent to the zoo? Join the circus? Become a hero? Find a way to change back? You make the call. You make the choice.

This book has the most unhappy endings of any of the other Choose Your Own Adventure books I read as a kid. The majority of endings involve being captured and sent to the circus, becoming a wildman and living in the woods as a beast, death, and becoming a laboratory test subject. Happy endings include becoming a media sensation, a hero for saving a child, and living your old life as a beast. There is only one ending that results in your character being restored to normal.